Exhibit 32.1

AMERICAN WATER WORKS COMPANY, INC.

CERTIFICATION

PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the quarterly report of American Water Works Company, Inc. (the “Company”) on Form 10-Q for the period ended June 30, 2009, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Donald L. Correll , President and Chief Executive Officer of the Company, hereby certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 as amended; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

By:	/s/ Donald L. Correll
	Donald L. Correll
	President and Chief Executive Officer (Principal Executive Officer)

August 6, 2009